The present invention generally relates to breastmilk pumps, and more particularly relates to a new and improved breastmilk pump with an effective and easy to operate manual pumping mechanism, a mechanism for one-handed or two-handed operation, and an improved vacuum regulator.
Breastmilk pumps are well known and generally comprise a hood body or breast shield that fits over the breast, a vacuum pump connected to the hood body for generating an intermittent reduced pressure or vacuum within the hood body, and a receptacle for the expressed milk. Examples of these pumps are shown in U.S. Pat. Nos. 4,857,051 and 4,964,851.
An aspect of the design of a manually driven pump has been the amount of effort required to use the pump. As the user""s hand tired, the suction created may decrease, as well as the stroke rate, thus decreasing the effectiveness of the pumping action. Manufacturing costs have also been a consideration because of numerous pieces that may be required in the construction of these pumps. Regulating the vacuum pressure created by the pumping action is also a consumer design consideration. Solutions to these problems are presented in this invention as are other innovations.
The present invention has a principal objective of providing a manual pump that is easy to operate. In one embodiment, vacuum is created by sliding a closed-end cylinder over a pump tube extending from the hood body. The user grasps the outer circumference of the cylinder and gently glides the cylinder over the pump tube. This pumping design is considered easier to manipulate than the traditional design of a movable piston rod reciprocating within a stationary cylinder. As applied to an inventive breast pump, the user generates reduced pressure or vacuum with a simple, nonstressful hand movement which utilizes better-suited muscle groups for pumping.
In addition, a locking means has been developed to prevent the cylinder from disengaging from the pump tube after reaching the position which generates the maximum reduced pressure (maximum stroke). The locking means is simple to engage or disengage, such as for cleaning of the pump elements.
Another objective of this invention is to provide an improved mechanism for regulating the vacuum created by the pumping action, which mechanism can be manipulated during use to adjust the amount of suction generated by a pumping stroke. One aspect of the present invention is having the regulator on the breast pump unit adjacent the hood body. A rotary member with an internal groove or passage communicating with the atmosphere connects to a ported structure and rotates about the structure to regulate the reduced pressure generated, by variously exposing the ports to ambient air. The reciprocating action of the cylinder over the pump tube then draws a predetermined amount of air through one or more of the ports to modify the amount of vacuum.
Also, while one of the goals of this invention is to provide a user with a handy, low-cost, low maintenance manual pump, aspects of this invention can be further modified to allow use with motor driven pumps.
In another embodiment of the invention, a lever drive mechanism is added to a piston-type pump configuration, which has a movable piston rod inside a stationary cylinder. The lever arrangement allows a user to operate the pump with one hand by grasping the lever and piston cylinder in one hand. As the lever is moved toward the cylinder, the piston rod slides toward the rear of the cylinder under action from the lever, creating a negative pressure in the pump. A spring action to return the lever, and the piston rod, to the starting position when the user releases the lever, can also advantageously be added. The relative position of the pump and lever makes the pump easy to operate and maintain its position on the breast.
In another aspect of the invention, a breast pump is adapted for use with one or both hands. Using the foregoing embodiment having the lever mechanism for one-handed operation as an example, the piston is provided with a handgraspable part that extends out of the pump cylinder. The hand-graspable part can be reciprocated independently of the lever mechanism for two-handed operation. One-handed operation is provided by the lever mechanism, and another two-handed mode is provided by holding the pump in place with one hand and reciprocating the piston with the hand graspable part of the piston rod.